I let a [M]iddle aged guy suck my cock for money

First post here, so please be kind.. So for context I’m 24, university student, pretty average body, I don’t know what else to say.. First of all, I’m bi-curious so I’ve done some things with guys, nothing too extreme.. I was roaming around the usual sex partner sites I use, I mostly just do it for fun or because I’m bored, since most of the time people either don’t show up or they just want naked pictures etc.. But, today was different. A middle aged woman sent me a letter stating, that she is searching for outgoing students to support. Now, I’ve never done anything like this before, but since I was bored out of hell I thought I would give it a go, why not, it’ll probably not happen anyway. But it did. She called me and told me she has a few middle-aged couples who are always looking for a third and they pay handsomely. At this point I thought I was either gonna get scammed or robbed or some shit. We set a time and a place not far from mine, I pack up my trusty military knife, just in case..