If I were him, in that very same situation, I wouldn't have gone. After all, it was obvious, from his own words, that he didn't want to go.
Unlike this spineless male mc, I would've just told my co-worker that "not interested, ask someone else" and if they would've kept on pestering, I probably would cut any ties I have with him outside of work. No point associating with an idiot who doesn't understand to stop when told so.