any variation of "I am not looking for a relationship/to get serious/to settle down/I'm only looking for fun"
to me that's a sign to run, far far away!
Its pretty obvious from the first hello.
You can see it in his pants.
I know I'm going to get flack for this.
If I've already slept with her before I've made this decision, it's going to open with something like "I don't think we'd make a good boyfriend/girlfriend couple. What do you think?" This has happened to me exactly twice, and both times this actually worked out OK.
It happens, ok? Sometimes the woman is aggressive and I really don't know who she is as a person until we've been going at it for a while. Sometimes the woman puts on a front that attracts me and I don't realize who she is until later. Women typically aren't straight forward with me about anything so it takes longer to get to know them... and due to the way attraction works, you don't always have time to get to know them before you sleep with them (the window of opportunity doesn't last too long after she has expressed interest, which typically happens shortly after meeting, though not always).
If I have already made this decision before I've slept with her, something like this will be said at some point before I sleep with her: "If you're looking for some harmless fun, I'm your guy." after I've already peaked her interest of course (when I know she wants me). I basically change my approach. I am thinking of one situation where this exact line was used. Her behavior changed after that, sure, (more reserved) but we still ended up having a good time later on. After sex I re-affirmed that this was my intent by saying "Please don't fall in love with me. I would not make a good boyfriend."
So I guess, if I haven't already slept with them I'm not exactly straight forward, but I'm not exactly subtle either until I have slept with them already (direct communication kills attraction very fast, but good sex builds attraction, so I'm basically relying on the memory of good sex to keep the FWB thing going after I'm straight forward); if I were in a situation where I didn't already know for "almost" certain that she knows what my intentions are, I would not proceed (this has not happened to me personally, where I was not almost certainly positive before having sex); I suppose if her tells have not changed or I am simply unable to read her and she's being aggressive about wanting sex I would have to be straight forward about it before sex which would likely kill her mood (luckily, has not happened this way for me yet).
Unfortunately, from my personal experience, even when all of this has been communicated, and when the woman has stated plainly that she's fine with just sex, she still ends up falling too hard down the road. If I were to enter into another FWB relationship at this point I think I would need to give her forewarning that other women have tried this and ended up falling for me at some point.
We pull out are d*** and say "You ready?" lol
Is this all you want? lol
Just dress slutty and walk into a bar. it'll happen
I would simply be upfront and tell her, and if she weren't down for it, respect her wishes. Seriously I don't know why so many men need to mislead, I know of plenty of women also only DTF.