Finally I have won Marcus' heart, though not completely yet. The success is near, I can feel it, so it is motivating enough to march forward. I think it helps that I have been collecting him from school, the 15 min cuddle on the way back gives me the chance to constantly whispering "I love you" into his ears, kissing non-stop and just spending our time together. And I have been taking him out more 1-1, so it helps that he is enjoying with me alone again.
He lets me put him to bed now on some nights and he goes to bed rather easily and happily. And he reciprocates with "I love you too", kiss me on my lips/cheeks and gives me cuddles freely whenever I ask for them. Nowadays he will acknowledge that "mama loves Marcus" with a big smile instead of the previous "no, mama doesn't love Marcus. Mama loves chic-chic and papa loves Marcus". Recently when I asked him if he wants to go on a cruise with me, he said "I want to go with mama and papa and Chic-chic". Aww.. my little family.