A man vile enough, and with such little respect for his wife and children, as to bring his affair partner into their home and have sex in his wife’s bed if that’s what he’s done, would not be the type to immediately confess to such a massive betrayal IMO.
It is a deliberate act of humiliation to his wife to have sex with with another woman in her bed knowing she’d be sleeping in that bedding apparently none the wiser a few hours later, getting off on knowing what he’d done there, thinking she’s too stupid to find out, so degrading and on another level to cheating in a hotel, on the back seat of a car or in the OW’s bed as she’s single.
He would likely deny, lie and make the wife out to be crazy with so much at stake and his standing with family and friends on the line which is why the OP has been advised to get incontrovertible proof of an affair if that’s what it is, so he doesn’t get that opportunity with her second second guessing herself and driving herself mad.
Being in full receipt of facts before making such life changing accusations is the opposite of being childish and playing silly games.
Confronting without them and possibly being gaslit, made to feel crazy, and on high alert, then realising later on he was cheating all along, perhaps when he leaves for an OW and tries to make out nothing was going on before then, would prolong the agony more.
No personal experience of this myself but keeping a cool head and doing a bit of digging/observation for a short period and knowing for sure either way with evidence that can’t be denied if it is the case, is a better outcome that driving yourself nuts and trashing your mental health with suspicion for months on end.