Many male guppies have 'black spots' but if by "black spot" you mean "gravid spot" then no, a male guppy can not be 'gravid' because gravid is the equivalent of "pregnant" and male guppies can not get pregnant.
She is pregnant! The dot is really the eyes if the fry (baby guppies). The bigger the dot the closer to giving birth!
No!
The black spot will not go away as it is the eyes of the fry through the pale skin of the guppy. As the pregnancy progressess, the (black) gravid spot will get darker, and the fry will mature.
That is quite common. Don't worry about it. A gravid spot does not have to be dark or black. Your guppy is perfectly normal.
Is it back near the anal fin? Although a picture would help it's probably the gravid spot. Pregnant live bearers get the spot and it gets bigger and darker the closer they get to giving birth..
If your female guppy is being or has been kept with a male then she will be 'gravid'. The colour of the 'gravid spot' varies.
Your guppy will be pregnant if it has been in a container with a male since it reached maturity. A none pregnant guppy is an unusual thing. She will develop a belly and also when seen from behind she will have a dark spot visible deep inside her on either side of her vent. (the gravid spot)
The Gravid female will have the dark "gravid spot" in front of her vent. I can however assure you that if there has been a male in the same tank with a female guppy for any reasonable length of time she will be gravid.
Your male guppy is female and with child.
If your female guppy has been in a tank/container with a male since it reached maturity it will be gravid (pregnant). Give it time. The fry will come eventually
It might want to mate with it.
All that is needed is a male guppy in with her.
it may be a femake or a FAT guppy
yes there are. that is how they get mates.