Dear Readers: This week I'm running "Best Of" columns while on tour meeting readers of my memoir, "Strangers Tend to Tell Me Things." Today's topic: relationships.

Dear Amy: I'm a 28-year-old straight male. My best friend and I rent an apartment together. He came out to me when he was 18, and I support and accept him.

A couple of months ago my girlfriend of four years ended our relationship. I was crushed. During that time, my best friend told me he had sexual feelings toward me. I told him I loved him as a brother only and did not share any sexual feeling toward him.

After that night, I thought everything was OK. But a couple of weeks ago he came home drunk. He crawled into bed with me and tried to be sexual with me.

I don't want to be in the same room alone with him right now. I'm not sure what to do. I don't want to lose our friendship, but how do I get the point across that I'm not interested in him sexually?

Amy says: Crawling into bed and coming on sexually to a sleeping person is assault. Sadly, like many victims of unwanted sexual contact, you seem to be blaming yourself and wondering what you can do to repair the relationship.

But he is the one who has disrespected and violated you. An ongoing friendship might be impossible. What happened is not your fault. It is his. You should think very seriously about whether you want to continue to cohabit with him.

If you want to have a friendship, you two will have to talk about it. He should apologize and assure you this will never happen again. If it does, the friendship is over, and you should consider calling the police.

Worth the wait

Dear Amy: I am 18 and have been dating my boyfriend for nearly two years. He means everything to me. Last year we both went to university in different parts of the country, so we were in a long-distance relationship. I was OK with it until I met a guy who gave me everything I have been missing. We were not really dating but had sex many times.

Earlier this week my boyfriend found out and broke up with me. It was only after he was gone that I realized he has always been and always will be my everything. I want him back, but he doesn't want to hear from me.

Amy says: Perhaps you've studied the famous "marshmallow test" in college. In this study, preschoolers were presented with a choice — they could eat one marshmallow now or eat two if they waited 20 minutes.This study demonstrates the relative ability of people to delay gratification in order to receive a larger reward later.

You have flunked the "marshmallow test" big time. You weren't willing to hold out to receive a larger reward (staying in a loving, long-term relationship) later.

My take is that you are probably still too immature to bank your two marshmallows for later. Let this be your wakeup call in terms of personal ethics. When you make an ethical lapse that hurts someone else, apologize and ask for forgiveness.

Send Ask Amy questions to Amy Dickinson at Twitter: @askingamy