The TVTropes Trope Finder is where you can come to ask questions like "Do we have this one?" and "What's the trope about...?" Trying to rediscover a long lost show or other medium but need a little help? Head to Media Finder and try your luck there. Want to propose a new trope? You should be over at the Trope Launch Pad.
24.107.197.80
Since: Dec, 1969
FloydPinkerton
Since: Nov, 2010
99.241.142.240
Since: Dec, 1969

This appears in perhaps maybe anime and live action even.
The male character becomes all maternal after caring for a helpless creature or infant or both.