My husband was actually quite jealous of my current therapist when I first started seeing him; in his BPD brain, I was abandoning him and falling in love with my therapist, which was crazy ridiculous and pretty delusional.
I actually encouraged my husband to go see my therapist and meet the man. He did and actually ended up using him as his own therapist which was completely okay with me; I sent him knowing that was a distinct possibility and really hoped that would be the case. I knew my husband would like him, would mesh well with him, and hopefully be able to work on his own issues while I worked on mine. (Husband realized pretty fast, by the way, that T would never have been my type and that T is extremely professional, so at least that resistance to my own therapy was quickly resolved.)
Our marriage has grown (not without growing pains

). Our communication is much more honest and open than it ever was before. With better communication does come more conflict at times, but it is conflict we are able to work through because we lay it on the table instead of just seething quietly about things. We've both grown as individuals, and at times my husband still feels a bit threatened my my growth (as I've progressed a bit faster and farther at this point), but the discussions about his fears and my growth are much more open and productive than they ever stood a chance of being before.