Congrats on your twins, mama! Ang stretching sensation na yan ay super common talaga sa 5 months, especially with twins kasi mas mabilis ang growth, pero since it comes and goes and parang stretching lang, siguro okay lang, pero please check with your OB just to be safe, lalo na dahil twins ka, para ma-rule out kung wala nang iba't ibang concern. A few of us mums with multiple pregnancies experienced the same thing, pero importante talaga na ma-monitor ng doctor mo para sure ka, especially kapag may ganitong discomfort na recurring pa.