ema answers question

Assalamualaikum and g'day readers.
today's entry is rather random. i got a question from a friend, a non-Muslim friend, and i answered super briefly. but the whole time, i've been thinking about how i should have explained to him more about it. 

hop on!

what was the question anyway?
he was on a motorcycle, fetching something when we met and he asked me where i was going, coz he wanted to drop me if it's somewhere near. i told him it's okay. that's when he popped the question. *of course he didn't ask me to marry him, he has a girlfriend already* he asked me if i can ride with him on a motorcycle. when i said cannot, he asked some more. 
"what if i put something in between you and me, can you still ride with me?" i smiled.
i explained to him the reason why a guy and a girl can't ride on the same motorcycle is as a preventive measure. it prevents one from knocking on the other or touching the other person. i didn't answer religiously, i didn't use the word Islam. i was afraid he might not be able to accept my answer. again, i didn't want him to get paranoid of me, so i used a different approach.
"imagine if you bring your girlfriend and you brake suddenly, see what happens? haa...like that la. so that's the reason why i can't ride with you lorr" he smiled.
then he asked some more. 
"if i'm your brother, you can ride with me?" i said yes.
"what if we just pretend we are siblings? if people ask, you just say i'm your brother la, 
can ah?" to be honest, i was doomed at that time. i had no idea what to say. but i answered this, i swear i don't know where the answer came from.
"you can lie to others, but you can never lie to God maa..." i smiled. he did the same.

to those who are still a little blurred, i don't blame you, based on what i told him, i don;t think he even gets it. here's the more factual and religious part of explaination.
Islam is a religion that is complete, covers all prospect of life. in this case, it's the way one mingles with his/her friends. it's okay if your intention is good, but you must remember the reason why Islam says no to some things. 
Islam prohibits one from coming into physical contact with another of a different gender, excluding the mahraams. *see dictionary below* this is because when one is not your mahraam, touching them or exposing our aurah is a sin. so, sitting super closely on the motorcycle, on the bench in the park, or even touching hands across the dinner table is a sin. 
regarding the statement i came across, about Islam prevents sins, that's because when Islam prohibits one from coming into physical contact with the non-mahraams, and the Muslims follow, then sins are not made. things will just stop there. imagine if this is not prohibited in Islam, the boy and girl are allowed to come into physical contact with one another, they develop this 'crazy in love' feeling for one another, and that leads to who knows what and ends up with you know what-conflict and problems. 
so, to me, Islam is a religion that prevents something from happening, only if one practices to be a real Muslim. 

Mahraam: people who you can never marry according to Islam. eg: father/mother, brothers/sisters, grandpa/grandma. *these people must be blood related. if you are adopted or they are your stepmother/stepfather, they are no longer your mahraam*

i know my writing is getting worse by the day. it's so hard to explain through writing. please provide me some feedback if you think i need to explain more or that you don't understand something. i will try to deliver better the next time around. 
thank you.