Yes, he was VERY paternal in the wedding ep. A lot of people seemed to see it as sexual attachment/attraction to Gwen, but it seemed to me more like a father who couldn't quite bear to give up his little girl. It also explains how Jack could actually be completely genuine in telling both Gwen and Ianto "I came back for YOU". And his challenging attitude towards Rhys, while at the same time INSISTING that Gwen keep a real life.

Poor Rhys. I'd be terrified if Jack was my in-law!