Cats can often develop fears of people that are new to a house for many reasons. As I have stated if a cat is friendly and comfortable at home, but freaks out when visitors are around it often relates to not having enough experience with visitors when the cat was very young. OR, sometimes the cat may have had a bad experience with a visitor when it was young. Other times, visitors are fine until the one time somebody comes over the cat doesn't know, and there is a storm outside, lightning strikes, thunder rolls the cat is terrified and they just know it was the visitor that caused that terrible sound. Cats are strange creatures. We will probably never know exactly what goes on inside their heads. Even if we did, it might not make sense to us.
Now, we do need to rule out medical issues always as cause of change. The defecation could be a sign that the pet is having intestinal problems. It might be very early, but many cats do have problems later in life with intestinal issues. If the pet is uncomfortable due to this, or other physiologic changes you might not be aware of, it can manifest in unusual activity for the cat. So, a complete exam with the Vet, a sample of the feces checked for parasites, and blood panel with urine sample is very important. I know it sounds like just tests that are not related to your cat being afraid of your boyfriend. But, in truth, many of these cases come down to just something simple like that.
BUT, for the ones that are not medical -
HOW TO RESOLVE THE PROBLEM-
1. prevention is the best - too late here for adult cats, but next time be sure to get the kitten exposed to as many different people as possible (color, wheelchairs, hats, glasses, beards) and reward your kitten when it approaches these people and intereact appropriately
ADULT CATS -
2. the treat and reward system for approching visitors and boyfriends works for adults too, and the following are things you can try
3. Have guests let the cat approach instead of approaching them - just freaks them out more
4. have the guest squat down low and sit on the floor - this makes them look smaller to the pet and less scary
5. avoid direct eye contact
6. you or someone your cat loves should give treats and encouragement with the visitor far away as needed to make the pet comfortable - play is ok too
7. cat won't come out of hiding? try opening a can of it's food or rattling a food bag to coak it out.
8. closing doors BEFORE the visitor arrives is a good idea so it can't hide in another room
9. if your cat can learn to remain calm enough to eat or play while remaining at a safe distance from visitors, gradually entice them to come closer with other special treats or toys. This might take quite awhile to build up the trust - may not be overnight
10. if your cat begins to come close enough, 10 feet or so, have the visitor gently toss a toy or treat near the cat, but not AT it obviously. A toy to the head is not a good way to make friends here
11. Cats don't have the longest attention spans. If your cat loses interest and walks away - leave it and try again later
ANTI-ANXIETY medication can and does help with fear as well ...
I have some information on that too... give me a second to retrieve that..
A product you might wish to use which helps to alleviate stress and provide calm in cats is called Comfort Zone by Feliway. (CLICK HERE) It is completely natural and is plug in that plugs into the wall. Very easy to use and does help.
In some cases, cats just like people need stronger medications to help them cope with difficult situations. Sometimes clomipramine, buspirone, even valium are used in these situations. Many people fear using medications in their pets. The think it might "dope up" their pets. They fear the pet's behavior will change and they won't be the same cat.
Two things to say about that -
1. we dose these medications to find the best dose for the pet without causing sedation to the pet
2. yes, it is likely your pet will change behavior on these meds, and not be the same pet. In fact, that is the whole goal in the first place!!! These meds often help your pet go BACK to being the pet you loved without the behavior changes that are the problem in the first place.
I also have some information on how to train your pet to not be afraid of thunderstorms (it seems in your information you stated your pet might be afraid of storms?) and would be glad to provide that for you as well. Just let me know.
I hope this has been helpful to you. If you have questions after you have read ALL of my responses, please contact me through this website. I might not be online but I will receive a message when I am online again and will respond as soon as I am able.