Can one mitzvah interfere with another – if so, which to chose?

So, there I was, putting on talis and tefilin before I go to work so my kids can say shemah with me in the morning.

Then my wife walks by and says, “There’s nothing sexier than a man putting on Tefilin.”

Okay then…

Well. Ego boost.

But now I’m left with a question: what if the kids weren’t there and my wife demands I perform another commandment with her…one that interferes with davening.

Which mitzvah takes precedence?

Discuss.