Hematolagnia (blood fettish)

I have recently had an experience with two friends, a girl and a guy who are dating, who cut themselves solely for the purpose of blood as a turn-on. Basically, i caught them cutting and eating eachothers blood when they were drunk. so i confided in my boyfriend on what i saw them doing and he said it was messed up and disgusting and i simply replied "people like what they like". that situation with them freaked me out at first but then i thought about it and started to like the idea of it. So one day when they were tipsy i told them how the thought of it turned me on and they asked if i wanted to watch so i said yes. i did and it was a total turn on but i also touched the cuts and the blood and ended up licking my friend's (the girl) fingers covered in my other friend's (the guy) blood. nothing sexual other then me licking and sucking her fingers so no cheating going on. i highly enjoyed the whole thing. so do i tell my boyfriend what i did with the blood or do i just keep it to myself because its not an ongoing thing.