I actually cannot understand why men lie about their dick sizes. It's sooooo pointless! You can lie about your size in message or in text but once people see your photos/ videos or even meet you in person, they will find out for themselves and it could cause your partner to be disappointed and it will just end up coming back to hurt you because you lied. Don't lie. It never ends well when it comes to anything.
Most of the guys I have met in person and online have exaggerated about how big their dick really is. This could be because...
1.) (Most Influential cause, in my opinion) The porn industry has given an inaccurate vision to men that only men with huge dicks will get more sex and are more attractive to either gender. This is not true at all. I have noticed, and I don't know about anyone else, but the porn industry advertises bigger dicks more than guys with average or smaller dicks because the industry believes that all people will like the same thing. It's specific and narrow-minded which is having an impact on men and their opinion on their own dick sizes. Men are starting to think that if they are not big, that they are not good enough and it's not that at all. When something is made more of a deal of or is more easily accessible, media can warp people's opinion's.
2.) (A chemistry myth that isn't always fact) Some men have been given the impression that the bigger the dick, the more pleasurable it is for their partner. This is not entirely true. Some women say they find it pleasurable, however, some women find it uncomfortable and the same for men. Some bigger dick's are more attractive and some are not attractive. I'm pretty sure that if you are turned off by a person's genitals, that might effect the chemistry on it's own, let alone anything else. If you don't have a big dick, that's okay. Be proud of it! Average dicks are just as much fun and can be equally as attractive.
3.) (Other people's opinion's effecting your own) Everyone has a different opinion on what is attractive and some people seem to think that their opinion is more important than others and so they spend their lives trying to persuade people to think the same way. I remember when I was a teen in school, boys would say that bigger dicks get you more sex, girls prefer it, size is more pleasurable, size is more manly and masculine and all that school boy shit, however, as I've explained before, it's all just a matter of opinion and is not fact. Spouting out your dick is 8 inches when you're actually 5 inches, is a sign that you're impressionable.
4.) (The wrong perception on a successful, long lasting relationship) Dick size is not the only thing people care about when they are in a relationship. Trust, honesty, mutual interest, good looks, height, hand size, feet size, body build etc. There are many different things about people that cause other people to find them attractive. We are all different and all look for different things. Dick size... is not the be all and end all. Not all people are shallow.
5.) (Low self esteem) We are all in different life situations and some people have it worse than others. These differences among human beings cause shyness, self hatred, self torment, timidness, lack of self awareness, etc and these mental flaws can also make a man feel below standard. Saying their dick is bigger than it actually is, possibly, is an escape, mentally, and they are able to feel more than average for a few minutes. Sounds odd, but I reckon this does happen.
6.) (Living in denial) A lot of guys don't measure their dicks properly. If you can't measure properly or you choose not to, don't expect others to go along with it. Insecurity is the under lying issue there.
There are loads of reasons as to why men might lie about their dick sizes. I would strongly suggest you don't lie. Protect your feelings in the long term, rather than a few minutes to feel good about yourself, when it's delusional.