One aspect of the present disclosure relates to a medical connector assembly comprising a male port plug and a female port plug that is releasably lockable with the male port plug. The male port plug can include a first end portion adapted to mate with a fluid source, and a tapered second end portion. The second end portion can include a twistable locking mechanism comprising a plurality of crescent-shaped flanges that extend annularly about less than the entire outer circumferential surface of the second end portion. The female port plug can include a central channel configured to receive the male port plug. The central channel can have a tapered portion adapted to friction fit with the second end portion of the male port plug. The female port plug can further include a receptacle portion adapted to receive the plurality of flanges comprising the locking mechanism.