Having a significant other, in most cases, involves some combination of sex and conversation. Sometimes these things are awkward, and sometimes they’re fantastic. It's a crap shoot, really. However, pick up any of the Mass Effect games and it's a 100% certainty that you'll get a generous heaping of the former: some creepy, prying conversations and very uncomfortable, not-erotic sex.
Best case scenario, you remind yourself that you might be better off alone and cruise through Valentine’s Day painlessly. Worst case? You take out your frustrations on some reapers and cry yourself to sleep. Absolute worst case? You drink too much, dial up an ex, and get at least half of the experience: creepy, prying conversation.