In my last two games, I’ve twice accidentally sent a relationship request to somebody I didn’t want to be in a relationship with. The first time (in beta 0.31), I did it by clicking on a log entry where my boss had become romantically interested in me (I don’t recall what the text said, but it appeared right next to the standard +2 relations with boss line from each day of work). That was especially bad because I was in a relationship with somebody else already (and they dumped me immediately). The second time (in my newly started game in 0.40), I misclicked on a search result and hit the “relationship request” button underneath it instead.
I would suggest that there be a confirmation dialog box that pops up when the game things you want to send a relationship request. This way, if you click it accidentally, you can back out without upsetting anyone.