Yeah, I think as far as Ianto is concerned, it's very obviously a Serious Thing. The whole deal with Lisa, plus the actually rather telling fact that Ianto is the ONLY CHARACTER who has never been shown to have casual sex (even Tosh, who is IN LOVE WITH OWEN, has had casual fucks on a number of accasions), kind of shows us that Ianto isn't really the kind of guy who does casual, and worse than that, I think that's something that Jack is more than aware of, which makes it all the worse that Jack's being shown to be taking such a flippant attitude towards the relationship.

All of which reminds me of the problem I had in season one with the relationship, and that was the implication that, if Jack KNOWS Ianto doesn't do casual, yet he casually fucks Ianto regardless, that makes "harassment" far less of a joke and far more of a reality, and it implies a slightly manipulative side to Jack, who has seen the depths of Ianto's devotion with Lisa, and the possibility that Jack has knowingly entered into this relationship, thinking that redirecting Ianto's obvious passion and devotion towards Jack would be beneficial for all concerned. Ouch.