A Purely Good Act?

Today I cleaned Liane's apartment! Why am I cleaning her apartment? As I cleaned I pondered this question, or should I say, while I cleaned I had the chance to ponder this question - when else could I ponder this?

...Or: while I cleaned I enjoyed pondering this thought! The obvious answer and one that isn't entirely false on this occasion is that I'm doing it to be kind to my girlfriend. But this is not the entire truth. Sadly, I somewhat enjoy cleaning! Furthermore - let me be honest - I'll also enjoy (derive pleasure from) Liane's reaction to the clean apartment.

If the sole purpose of my cleaning the apartment was to please Liane then I would claim that I am doing a purely good act (implying that I don't derive any pleasure at all from the deed) but I enjoy the cleaning, I enjoy the cleanliness too(!), and I'll enjoy Liane's reaction. I can't claim this is a selfless act, a purely good act.

If we judge the act from a deontological perspective we could claim that the act of cleaning was good in itself, without regard for my motives. But, from a teleological perspective my motives are arguably tainted by self-interest regardless of the act itself.

Considered universally, can we truly claim that any act is truly selfless - a purely good act? No matter how selfless an act, is it not tainted by some self-interest, some personal gain, albeit just the satisfaction for doing a good deed for someone else?

What then is a Purely Good Act?