Be a lion. Do u know how lions hunt? It’s definitely not like in bollywood movies where the hero challenges openly. Lions hide and wait for the perfect opportunity to strike. Hire a pvt detective. And track her locations she visits. Once she is in a hotel/room with her partner catch them there.
FYI – while catching don’t go alone. Take some people with you. Use a bodycam to record while they are in bed and you caught them. And make a scene out of it, shout at the top of your voice infront of everyone (so loud that neighbours come quickly) while they lay naked in bed. And make sure that it is viral. Congratulations friend you just proved adultery. The question is will our shameless judiciary still bother you or leave you for that you need a good lawyer.