*winces slightly at prior post* The thing to remember about "all in your head" is that what's in your head can indeed affect the reflexes -- if you're expecting pain, and you tense up, you're more likely to get pain. Knowing this... It's a reflex, it's not necessarily under conscious control. (The extreme end is vaginismus!)
While you may not be objectively "tighter," you may not be prepared, relaxed, or used to the sensation. If you don't masturbate with insertion of boyfriend-sized toys, your vagina is going, "Woah! Wait, what is this thing?" And your muscles may reflexively "blink" down there, which is literal tightness and can make things painful if you try to go on.
If you can go slower, with lots of foreplay and lube, that would probably help. If you've got enough endorphins in your system, a minor amount of discomfort may not register as pain so much as "whee, more sensation!" If you can masturbate with insertion, to remind your body "no, really, this is fun!", that might also help.
no subject
While you may not be objectively "tighter," you may not be prepared, relaxed, or used to the sensation. If you don't masturbate with insertion of boyfriend-sized toys, your vagina is going, "Woah! Wait, what is this thing?" And your muscles may reflexively "blink" down there, which is literal tightness and can make things painful if you try to go on.
If you can go slower, with lots of foreplay and lube, that would probably help. If you've got enough endorphins in your system, a minor amount of discomfort may not register as pain so much as "whee, more sensation!" If you can masturbate with insertion, to remind your body "no, really, this is fun!", that might also help.