If he exhibits BPD characteristics then I would suggest therapy specifically DBT, unfortunately that suggestion probably shouldn't come from you.

There is good news, Even without therapy he can get better at managing emotions and relationships as well as minimizing the more flighty tendencies.

For me there were three factors that lessened the intensity of my BPD characteristics. The first was establishing a long term relationship, the second was age (it seemed to fade a great deal at 30), and the third was knowing that my wife would leave if I didn't respect boundaries (she actually did leave for a month)

I would recommend reading a book called Stop Walking on Eggshells it has great relationship advise that works for anyone but is written specifically for loved ones of BPD. Most libraries have at least 1 copy (although ours is reserved for nearly a year and a half out) In this book there is an entire chapter about setting boundries.

I would also suggest watching some videos on youtube here is a quick list:






I would also recommend just about any relationship skill video you find.

Now if he has BPD one of his biggest fears is abandonment by people he loves, that would be you. Make sure that he knows there needs to be compromise otherwise the relationship can't work and you will need to leave. I know it sounds maniputive and it is but sometimes it is the only thing that works. Before setting those bondries I would read the Walking on Eggshells.

Hmm that is an expensive list: The two that standout to me would be clothing design you can get magazines or other cheep art supplies, such as marker sets or a sketchpad. Japanese culture is much easier, you can get caligraphy sets for less then $20, the library has a plethra of books on bonsai, buddism and the Taoism (The Tao ta Ching is great) if he is intrested in religion, Japanese language primers, and old kung fu movies. Many martial art studios offer a 60-90 trail period or at least reduced price. You can get 20 trident maple seeds for $5 for bonsai, There are tons of amines online if your willing to watch them with him, Ramen recipes can be found all over online and are cheap to make, find pictures of kimonos you like the looks of so you can discuss the design aspect with him.

Obviously if you can find mutual enjoyment out of any of these t can strengthen the relationship. If not you can still use some of these ideas as positive reinforcement for good behavior.