Sometimes people lie or bend the truth in order to protect themselves. They're afraid that people will reject them if they know the truth about them and it makes them insecure. Some people can take this to an insane degree of lying, while others will tell little white lies that are understandable and forgivable.
Maya's clearly been hurt before when people have found out about her, especially her father which is the most hurtful thing because the father daughter relationship is considered an important component of a girl's life. To lose that unconditional love with one of the first and most important objects of her love is devastating and it's understandable why it may affect her trust in others, especially men. She may also have been bullied at school, either for being gay or suspected of being gay, and even in this day and age, this type of bullying still happens.
Her defense mechanism is to say she has a boyfriend to try and put guys off, but as she starts to trust the MC she tells him the truth as her guard is slowly starting to come down and she feels she can trust him. Her and the MC can then start to get more intimate, and perhaps she could have told him at some point or another, but I feel like she simply wanted to enjoy this intimacy and to explore these feeling for him without the Josy baggage around both their necks. It might seem like bad judgment on her part, but she's young and inexperienced and people like that make mistakes.
When you're backed into a corner you'll do whatever you can to get out of it. Maya felt backed into a corner with her need for tuition and Quinn offered a way out. What Maya did, to me, feels more like a harmless prank than manipulation. I also don't recall Maya getting jealous when the MC came back because I was honest with her and told her exactly where I was going and what for, but if she is upset because you don't tell her, this likely goes back to her feelings of mistrust I mentioned earlier.
She shared an incredibly intimate moment with the MC that was as close to having sex as they could get. This gives her a moment of clarity where she feels how deep her feelings for him are and how much better she feels being with him than feeling so hurt in her relationship with Josy. It is convenient that Josy shows up right then, but that's all part of the drama, right? Her excuse about not having the chance to tell him is wrong, you're right about that, as she did have ample opportunity to tell him, but like I said, I view that as being her not wanting to quash a potentially good thing by bringing her relationship drama into it. She might have thought it was the right thing to do, it wasn't, but I can understand it if someone did that.
Not everything is black and white and someone who might tell a few small lies about themself could be totally honest and forthright in other aspects of their life. Maya either didn't think the HOT tasks should be cheated or simply didn't consider it as an option. After all, taking porn videos from the internet or using a dildo does seem like something you could easily be caught out by as it could be easily seen as fake, so why risk it? It's the MC who makes her feel confident that it can work and she believes it because she trusts him, but she didn't believe it before because she lack confidence in herself. (I still don't think it will work, however, and I think they'll soon realise that too.)
Yes, Josy's more honest about it because she's a more confident, straightforward sort of person. Just look at how she addressed Quinn the first time they met. Maya on the other hand has more of a wallflower-type personality; guarded, insecure, and lacking in confidence. She doesn't easily express herself because of this and it can lead to a lack of honesty, but it's not done maliciously, it's an involuntary reflex to keep people at arms length because she's afraid to let them in. That's not something to get angry about, it's something to feel pity and empathy for.
But, hey, difference of opinion, right?
Agree to disagree.