I've often had male friends and female friends who have asked me to be their +1 and I have done the same, but I do expect them to be friends ie, folks I can call for help, discuss what's on my mind, share my life in other ways with, see regularly. I guess you want these guys to pay for you to be a plus 1? Are you expecting this of female friends, too? Or are you saying their not doing their friend work? I love spontaneous invites, always have, but you're entitled to your rules and preferences. I AM frequently busy though and have no bones on telling people so. My sexual availability is more inside relationships than anywhere else. There are some exceptions but not many and it's not a given.