i hope that title makes sense – i have a good friend who i fell out with when we were teens and recently reconnected with after many years of no talking. we've been having a ton of fun hanging out and doing stuff together again. they shared with me that they have bpd (my wife does, too, so i have some knowledge) and that i was their first FP before they really knew what it was. 

they recently expressed that they're afraid of FP'ing me again. i understand that i can't really control whether i'm put in that place in their life, but if it happens, i don't want to make it any more stressful or upsetting than i know it can already be. is there anything i can do to help my friend or support them if i become their FP? do i just stay as i am and support them when they specifically need it, or is the status of an FP something that should be discussed so there is more understanding ahead of time?

i really care for them a lot, they're a good friend and i've been so grateful that we've been talking again and that they've been so understanding about my own issues. i just want to make sure i do what i can to accommodate and help. advice?