how do i catch him if he's cheating?

problem/goal: i currently have a suitor. previously, he's a player talaga. which is normal and acceptable for me kasi some people really do have their hoe phase. we're fine naman, not until now na parang bigla na lang ako nagkaroon ng kutob.

context: I'm (20F) currently in a situationship. In fact he's (22M) already courting me na. lately, bigla na lang akong nagka instinct na something is not right, parang niloloko ako. whenever magkasama kami, lagi siyang naka dnd. hindi niya pinapahawak phone niya sa'kin, and i don't want to borrow it naman kasi that's kind of annoying lol esp hindi pa naman kami. and lastly, kapag matutulog na kami nakasingit lagi phone niya sa shorts lol. ewan ko kung dala na ito ng trusts issues ko pero there are girls, girlS, who are consistently reacting sa mga shared posts niya sa blue app. i hate this feeling hay, pakiramdam ko ang toxic ko for assuming things na walang proof.

so, paano ko ba siya mahuhuli in ways na malalaman ko talaga lahat? i want to investigate silently, give me tips please.