sex with him

Alright so last night my man and I were having sex..... as soon as he put it in he said I never know if it's in anymore..... don't know what thats suppose to mean but we just continued having sex and like 10 maybe 15 minutes into us having sex his dick went soft.... I asked him what happened and he said he don't know and I looked at him and said looks like you lost interest... and he said there's no way unless my dick has a mind of its own.... I don't know how to take this.... just last week we had sex and it was the best sex of my life but this week all of this happens....