I think Luke was probably very easily influenced when in Morag's company constantly. Changing his wardrobe, dressing up like a fireman and stripping while listening to her braying, it just wasn't him at all. Afterwards, when she'd asked for some space and he was back home away from her, he obviously listened to people who know him well and realised that it was pointless trying to make it work, to be someone's project and I think he felt embarrassed, which is why he retaliated the way he did.
Based on what we saw I think it must be absolutely exhausting to be around women like Morag and Amy. On the other hand, Bob and Meghan didn't work, cut their time short, but now seem to have a lovely friendship going on.