My girlfriend's phone habits are driving me nuts – anyone got real solutions?

[jackwolf]

Hey guys, long-time lurker here but I gotta vent. My gf (together 2 years) suddenly changed – phone always face down, takes it to bathroom every time, giggles at texts at 2am, then says "nothing, just memes". I tried asking straight up but she gets defensive and flips it on me being paranoid. I don't wanna be that controlling bf but the doubt is eating me alive. Is there any way to actually see what's going on without her knowing? Like real evidence, not just guessing. Apps, tricks, anything? Don't judge please, just need advice from people who been through similar crap. Thanks in advance.