Why should one need to ask for love? In a romantic relationship, when you need to ask for love, there must be something wrong; not exactly wrong with you, but there might be a weak link somewhere in chain. He, his problems, she, her problems, they, their own collective problems, something starts wearing off somewhere. It is the time when you feel left alone.
Seems like I’m giving more importance to the problems. May be; but those are pretty much complex, certainly unexplicable in words! I can certainly not answer you question “what happened?” at the end of the day.
There is always a graceful way to ask. Take initiative, and do take care that your partner is ready for it.