Literally it means something like 'it happened with joy/pleasure'. I'd say it's used more in situations with strangers, in shops, on the phone with clients etc. With friends, I'd say either
- nothing or mumble 'schon gut', 'ist doch klar' or something
or, if it was a bigger thing: Das hab ich doch gern gemacht/ Für dich immer
But a more concrete situation might help with suggestions.