Uhm, background checks, that is a possibility.
I opt for a different approach. Just go along with the flow, but make sure you spend quality time (ie 24x7 for days, perhaps weeks, perhaps even months) with your new partner, before committing yourself to that person 100%. I suppose, that was why in previous generations in the western world, one always said, first spend a vacation with each other and then decide if it is going to work or not. Albeit spending a vacation is a good step, I always say, vacations aren't the best suited for this since both are in vacation modus, away from home, friends and whatnot. Best to just do this at home, in the normal life both have and figure out if this bond can be strengthened or fade away after the pink glasses wear off.
Sure that's a good way too because happiness and fun comes first but after sometime they fade gradually in most cases thats when someone shows their real character. Like my cousin sister once told me. She said to know a womans true character, once in awhile do things that will annoy her very much.