My first reaction when reading "I need to know whether a situation is classed as rape or not" was that this may be on topic but is definitely way too broad. In order to make the question technically acceptable you need to explain the rules of the world where this situation occurs, and also, depending on the rules, the status of the deceiver and of the deceived; but then, if you explain the rules, then it may be case that you will already know the answer.
To illustrate the broadness, I will give an example.
In Jacques Offenbach's Orphée aux Enfers (Orpheus in the Underworld) there is a great scene where the gods and goddesses of Olympus taunt Jupiter by exposing his womanising adventures; in particular, Minerva sings:
"Pour séduire Alcmène la fière, tu pris les traits de son mari! Je sais bien des femmes sur terre pour qui ça n’eût pas réussi!" (In order to seduce proud Alcmene, you took the appearance of her husband! I know many women on Earth for whom this would not have worked!). (Words by Hector Crémieux).
This is a humorous retelling of the origin myth of Hercules. You are supposed to know that; or, to be honest, forty years ago well-educated Eastern European teen-agers were supposed to know that.
So what do we have here?
In Greek myth, this is a bog-standard matter-of-fact run-of-the-mill trick commonly used by gods to enjoy the favors of mortal women. Nothing special, tricked you! Note that the main conflict in the life of Hercules arises from the jealousy of Zeus's wife Hera, and not from any resentment on the part of Alcmene or her husband Amphytrion.
In 19th century Paris, this was absolutely perfectly acceptable in a comic opera; the public was supposed to laugh at the couplets describing Jupiter's (actually, of course, Zeus's, but for reasons French people always used the names of the Roman gods when speaking of Greek gods) amorous encounters.
But were the story set in the world of today, this would not work as light entertainment at all, given that at the bottom of it Zeus has sex with Alcmene without her informed consent.
Jacques Offenbach was a famous French composer of comic operas and not only. In Europe he is well-known, and his operas are regularly shown.
Orphée aux Enfers is a splendid comic opera. It has the distinction of featuring Public Opinion as a singing character, and it is the source of the best known tune for the French Can-can, which is featured in two separate scenes! (The tune, not the dance. The goddesses don't do the can-can.)
Alcmene, wife of Amphytrion, is of course the mortal mother of Hercules.