Statistically your relationship will suffer as in separation with someone you were with pre-pro flying. Most the time it's such a major lifestyle change that they can't handle it. You should probably know, does you GF call you every hour you're not with her? Then that's a bad sign. You're more likely to have stronger relationship with someone who understand what it means to be a pilot, not being 1st year FO also helps. It's all about the benefits. What ever you do don't have any kids unless you're sure they're the one. I can't tell you how many pay child support on $21 per hour, it's sad.