Embarrassed to have sex

I always pleasure my boyfriend by giving him head and wanking him off and now I really want pleasure back but every time he tries to finger me or when we’re close to having sex I always say no when I really really want him I’m so horny for him,he probably thinks I never shave but I do and the reason why I dont him is because I have a massive birthmark on my leg and I’m scared he’ll leave me when he sees it because he’s quite judgmental